Chitosan-Based Nanoparticles for Intracellular Delivery of ISAV Fusion Protein cDNA into Melanoma Cells: A Path to Develop Oncolytic Anticancer Therapies.

Oncolytic virus therapy has been tested against cancer in preclinical models and clinical tests. Evidence suggests today that the virus caused cytopathic effects associated with the formation of protein-mediated syncytium fusogenik and immunogenic cell death of eukaryotic cells. We have previously shown that the body of tumor cells generated from cells that express the protein fusogenik infectious salmon anemia virus (ISAV-F) increase crosspriming and display antitumor activity against melanoma tumor prophylaxis. 

In this work, we evaluated the effect of the expression of ISAV-F on B16 melanoma model, both in vitro and in vivo, using chitosan nanoparticles as transfection vehicle. We confirmed that the B16 tumor array  cell transfection with chitosan nanoparticles (NP-ISAV) allows the expression of proteins ISAV-F fusogenically active and reduced cell viability for syncytium formation in vitro. 

However, in vivo transfection induced delay in tumor growth, without a change in the lymphoid populations in the tumor and the spleen. Overall, our observations suggest that ISAV fusion protein expression using chitosan nanoparticles induce cell fusion in melanoma cells and antitumor response slightly.

CB1 cannabinoid structure-function relationships fourth intracellular loop-phosphorylated receptors.

A peptide consisting of C-terminal intracellular juxtamembrane circle 4 (IL4) of the CB1 cannabinoid receptor has three Serine residue (Ser402, Ser411 and Ser415). Here we report the effects of CB1 IL4 Ser phosphorylation of peptide conformation and function of cellular signals using nuclear magnetic resonance spectroscopy, circular dichroism, G protein activation and cAMP production. Circular dichroism studies show that phosphorylation of various residues Ser induced helical structure in a different environment. NMR data showed that helical content varies in order IL4pSer411> IL4pSer415> IL4> IL4pSer402. 

Efficacy of IL4 phosphorylated peptides in activating Go and Gi3 ([35S] GTPγS binding) and inhibit the accumulation of cAMP in cells is correlated with changes N18TG2 helicity. Treatment of cells with bradykinin, which activates PKC, plus a CB1-mediated inhibition of cAMP accumulation, and this was reversed by PKC inhibitor, suggesting that phosphorylation of chromatin serine may be modified physiologically relevant in vivo. We conclude that changes depending on the helicity of peptide phosphorylation CB1 IL4 can improve the effectiveness of G protein signaling.